ZOTAC GeForce GTX 680 Graphics Card SLI Performance Review

FXAA and TXAA

As we noted earlier in the article with the launch of GTX 680 and the R300 drivers NVIDIA are enabling the option to turn on FXAA in the driver control panel. This will force the card to use FXAA in any game that launches. FXAA uses the CUDA cores within our GPU to apply a post processing step (deferred shading) which reduces the aliasing on object edges, otherwise known as "jaggies". Through using FXAA the image receives a quality boost similar to 4xMSAA with less of a performance hit. Quality examples are shown below.

In future drivers NVIDIA will also be introducing TXAA. TXAA is a mix of hardware multi-sampling, custom high quality AA resolve and an optional temporal component. TXAA1 has a performance hit similar to 2xMSAA with quality above 8xMSAA. TXAA2 drops performance by levels around 4xMSAA while increasing image quality beyond 8xMSAA. Again, here are some examples.

TXAA is not available for us to test now but we can look at the performance levels offered by FXAA and MSAA as well as our own image quality examples.

Off all the results in this article the above image quality comparisons and framerates show the most clear cut win. FXAA offers better IQ than none or 4xMSAA and higher framerates than the traditional method by some way. The bonus is that by default turning on Anti-Aliasing in-game actually enables FXAA rather than MSAA.